worldcup spread sheet

Here is my spreadsheet

4 rules of flux lines

1. they always radiat from north to south.

2. they never intersect.

3. they cant be broken.

4 they always try to shorten themselves.

what will the test tommorow contain?

i think these 8 topics will be covered.

1. vectors
2. resistor color code
3. E 12 & E6 range
4. multimeter comparison
5. conductors
6. temperature equations
7. networks
8.Si units

Resistor network

 If R1 = 97Ω,
R2 = 41Ω, R3 = 9Ω, R4 = 8Ω, R5 = 6Ω, R6 = 54Ω,

This is a Resistor Circuit, to find the total resistance you:

1. redraw circuit, add R3,R4 and R5 together so you have one resistor in parallel with R2.

2. calculate the combined resistance of R2 and R3 (made up of the old R3,R4 and R5) by placing them both under one and adding them.

3. find total current, V/R=I

4. use ohms law to find any other value required.

E12 resistor chart

here is my E12 resistor chart

Parallel Circuit

This is a parallel circuit, the current has 2 or more paths to follow so this allows the circuit to work even after the loss of one or more components. the equation for working out the values in slightly more complex than for the series circuit because the resistance values have to be added as fractions. the voltage is the same across all branches and the total current is the sum of the branch currents.

Series circuit

This is a Series circuit, the current has only one path to follow, if any of the components are removed then the current will cease to flow. the total resistance can be easily calculated by adding the individual component resistance. from there its simple ohms law for the rest of the values.

Resistor color code chart

we have recently been exploring the colored band on resistors, the chart above is an invaluable tool in being able to read and comprehend resistors.the resistor above the chart has a value of 22 ohms with a tolerance of 5%.